Imouto Sensei
by Sentilusional
Summary: After revealing that she has been dating another girl to her family, Honoka's finds out that her little sister had a little secret of her own. Yukiho, being just a little more experienced, decided to give her big sister some dating tips and Honoka gladly accepts.


**Author's Note:**

For those who have read this story already, I revised parts of it and made some adjustments so please give this another go. The story is mostly the same so no re-read is required to understand the sequel, but I recommend it since it explains some of Yukiho actions in more detail.

If this is your first time here please enjoy this read and as I said above, there is a sequel coming so please look forward to that as well, thank you.

Cover image by: 京桜えな (Pixiv id: 4608546)

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 **Imouto Sensei**

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After a lengthy discussion with her parents, Honoka was given the okay to date another girl. More specifically, Kira Tsubasa, the ex-leader of the school idol group A-Rise. It has been two weeks since Tsubasa confessed to her and now she has finally mustered enough courage to tell her family. They accepted the fact that their oldest daughter was in a homosexual relationship pretty well albeit there were a few conditions for when her girlfriend was going to sleep over. Now she just had the rest of Muse to tell; hopefully, they will accept their leader dating their rival's ex-leader as openly as her parents did.

"I can't believe mom was fine with you having a girlfriend." Yukiho sighed while she and her sister left the Livingroom from the recently dismissed family meeting and headed upstairs to their respective rooms.

"Yeah…I was kind of nervous, but I guess it worked out." Honoka replied with a liberated expression covering her features. "Worked out...Sounded like she was about to start arranging your wedding." Her little sister countered with a wistful look.

"Eeeeh~?! I think it's a bit too early to start thinking about marriage."

"Onee-chan, the blush on your cheeks doesn't seem to agree with you." The younger Kousaka retorted just as they got to the top of the stairs.

"…"

"Not going to reply?" A smug faced Yukiho looked at her sister trying to hide the blush by looking elsewhere.

"Good night," Honoka said quickly, still avoiding her imouto's gaze as she hurried to her room if as Tsubasa herself was waiting for her in there.

Yukiho sighed for the second time while watching her sister retreat into her room down the hall. 'You really have changed since you started dating her.'

…

…

A few days have passed and Honoka has yet to inform the rest of Muse about her relationship. It seems another two weeks will have to pass for her to possess enough courage to tell another soul. Noticing the lack of news from her "friend" Alisa, Yukiho found herself in front of her sister's room door one night seeking answers. At least that is what she told herself.

"oh Yukiho, what's up?"

"Can I come in? I want to ask you something."

"…sure." The ginger noticed something was off with her sister but figured it was the reason why she wanted to talk.

A full head of burgundy hair rested on Honoka's pillow as Yukiho made herself comfortable, flipping through one of the manga she retrieved from her sister's shelf. "So what's up with you and the rest of Muse? You haven't told them yet, have you?"

"Mou~ really…you could have asked me how my day was or something before jumping right to that question." An exasperated Honoka sat on the edge of her bed. "And if you're going to lay on my bed don't spread out and take up all the space."

Yukiho complied and shift herself so that her big sister could sit beside her. "So…onee-chan, when are you going to tell them?"

"Ah–well…I tried to, but it wasn't as easy as I thought."

"Of course it won't be but you still have to tell them."

The ginger sighed as she allowed her upper body to fall backward, resting her head on Yukiho's stomach. "I know but that doesn't make it any easier."

'Can she hear how fast my heart is beating?' The brunette thought, seeing that her sister's head rested on her stomach. "Onee-chan…did you gain weight again?"

"Eh?!" Honoka shot up and stared at her little sister wide-eyed. "But I only ate 18 dumpli-"

"Jeez, I'm just joking. You don't have to get so worked up."

Honoka relaxed and laid back on the bed but next to her little sister this time. 'Thank god' the younger of the two exhaled silently as her plan worked flawlessly. "…but you did feel a little heavier."

"Yukiho!"

"Haha-sorry I just had too." Yukiho observed a blush forming on her sister's face. "Could it be that you're trying to look good for Tsubasa-san?"

The person in question shifted on her right side, turning her face away. There were a few moments of silence before she spoke. "You know you could tell them for me…"

"Nope." The younger one stated plainly. "You have to tell them yourself."

Honoka turned back towards her imouto. "Pleasseeee~!" Yukiho closed the manga, clearly not being able to focus on its contents.

"Now you just sound like a child asking for candy."

"Hey! Since when were our roles flipped?"

"Since you— hey! I'm not a child!"

"csk–you were just about to admit it," Honoka hissed her teeth vainly trying to contradict the smile on her face.

"Ha Ha," Yukiho replied in a monochrome voice. "Very funny." but with a smile also on her face. There was a temporary but reassuring silence as the two sisters just relaxed next to each other. They enjoyed that sweet and faint but ever-present smell of fresh bread, the muffled sound of wind wrestling with trees, and that distinctive sense of comfort and warmth they felt inside. This little moment of tranquility gave them a brief reminder of all the times they have spent together since Yukiho's birth. The young Kousaka could not remember a day in her life where she had not seen or heard from the person she looked up to the most even if Honoka was a bit—okay, a lot more than a bit—absent-minded at times. When she was young and the family business was barely starting up Honoka was the one to take care of her. Now, it could just be a simple phone call while one was away on a field trip just to see how each other was doing or sending pointless texts to each other throughout the day; it all stopped at some point and Yukiho missed it all…but when? When did it stop?

Was it when Honoka entered high school or when she created Muse? Maybe she didn't recognize it herself but that might have been when she started to get lonely.

"You know, it's been a while since we got to spend time like this and just talk." The ginger started.

Honoka's comment brought Yukiho back from her thoughts. "Yeah…it has."

Honoka twisted her head and gave her little sister an accusing look. "All thanks to you hardly staying home. Your big sister misses you sometimes you know."

"Sorry but I've been sleeping over at Alisa's house a lot lately." Yukiho hated to admit, she couldn't do that to her friend, but she knew she was using Alisa as a replacement.

Honoka now shifted on her left side to face Yukiho, subsequently moving a little closer to her while using her left arm for support…not that her absent-minded self would let her notice. "I know but why so often, it's not like you're…dating…her." As the ginger finished her sentence her imouto's faced turned a bright shade of red that could have been used as a nightlight. "Yukiho?"

"Y-yes...onee-ch-chan." Forlorn thoughts were immediately forgotten as Yukiho tried to act like she wasn't flustered but her mouth betrayed her.

"You're not actually dating Alisa, are you?"

"M-maybe…maybe not…"

Honoka was not convinced. "Yukiho."

"Okay, yes, yes I am." Honoka's sister admitted with her face threatening to set the bed on fire.

"For how long?"

"About 2 months now." Yukiho's muffled voice replied from the pillow her face was trying to set ablaze.

Honoka shifted back onto her back and stared at the ceiling. "My own little sister has been dating longer than me…" She sighed. "Congratulations."

While Yukiho was no longer a fire hazard she was a bit surprised and…disappointed? "Wait, so you're not mad at me?"

"Why would I be?" Honoka kept her gaze on the ceiling with an unreadable expression on her face.

"For keeping it from you."

"Hmm, I'm sure you had your reasons. Just look at the situation I'm in right now…if anything, I'm happy for you." By now the brunette face cooled down enough for her to look at her older sister, well that's what she thought as she sat up in the bed.

"You don't sound happy though."

Now Honoka sat up. "Because that means we won't have much time to spend together with school and everything else." A smile graced the younger one's lips at the words from her big sister. It was strangely satisfying to know that her big sister felt the same way she did.

"I will always have time for you onee-chan," Yukiho said as she hugged her sister, the sudden warmth catching Honoka by surprise before returning the hug. As they embrace each other Honoka detected something. "You know, your hair smells good." Tingles shot down Yukiho's spine when she feels her sister's warm breath on her neck. "Have you been using my shampoo?"

"M-maybe." The brunette replied, trying to keep her voice steady but Honoka detected another smell. "You've been using my body wash too…"

"Sorry"

"Mm, don't be. I like how you smell."

"Th-thanks" It is becoming harder for Yukiho to keep herself calm with the periodic warmth wandering the surface of her neck at her sister's every breath. Her face began to radiate heat but luckily Honoka didn't notice since she was preoccupied with the thought of kissing her little sister's neck that made her realized how long they have been hugging; subsequently, her own face started to warm up the room. Still, after realizing the length of time they have been embracing, neither wanted to let go. A feeling—no an urge of want came over them, one they both recognize from spending time with their respective girlfriends. But this was different, it felt like a deeply rooted desire to be with each other, an inclination to explore each other, a longing to feel something they knew could only be from each other. This need, to put it lightly, excited them in an unusual way but it was also frightening. They were afraid that if either were to give in they would do something they could regret later.

Gradually they inched away from each other, no longer hiding the flustered look on their faces. 'Did I just get turned on from hugging my sister?' Honoka thought as an awkward silence enveloped the room. 'I'm turned on just from hugging onee-chan?' Yukiho also thought.

Honoka spoke up in an attempt to get rid of the steamy air around them. "S-so…how far have you gotten with Alisa?"

Yukiho heart skipped a beat.

After hearing the words she spoke, the ginger internally yelled at herself. 'Why did I have to ask that?!'

"We-well we've ki-kissed…"

 _she's actually answering me!_

"and made out a couple times…" Oddly enough, Yukiho didn't have a problem telling her sister the details of her relationship. It was still embarrassing but it just felt natural to tell her big sister anything.

"o…ohh"

"That's it. I told her I didn't want to do anything else yet."

"o…ohh" The ginger repeated, attempting to stop herself from saying anything else she will regret.

"Wh-what about you o-onee-chan?"

"…"

"Onee-chan?"

"uh? Ah, umm…we-well we didn't do anything yet." She shouldn't have been but Honoka was surprised when her question was redirected at her.

"Hmm~ well we've held hands before."

"No kissing?"

"No…I didn't really feel comfortable doing it yet."

For some reason, Yukiho was relieved at hearing those words; her sister has been dating another girl for over 2 weeks and they never kissed. Being too flustered and constantly forcing certain thoughts from her mind, she didn't think any further into the answer she received.

"If you want, I could teach you how to kiss." Yeah…pushing those thoughts away was futile in the end as Yukiho lifespan probably dropped a few years by the level of mental shock her own words gave her.

"O-okay"

 _She agreed!_

Whether it was from genuine excitement of what was to come or just being shocked, the brunette almost fell off the bed at her sister's reply. After she recovered from either or both she slowly leaned in to kiss her big sister. Honoka subconsciously dismissed her dramatic reaction since her mind was focused on the fact that she was going to kiss her little sister. She didn't think much of it. It was just a kiss. It's not like they were in an immoral relationship or had ulterior motives. Nope, none whatsoever.

With Yukiho it was a similar story, she felt comfortable with the thought of kissing her sister, she figured it would just be like when Alisa kissed her but then why is she getting flustered? She was hesitating, examining Honoka's eyes as if asking for approval. She received it when Honoka brought herself closer, looking back at her expectantly, eyes almost pleading with her to close the gap between them and so she did.

'It's Just like the simple kisses I share with Alisa.' Yukiho thought as she got closer. But she was so wrong, much to her surprise and later satisfaction.

Time seemed to stop as their lip's meet. The softness of each other's supple lips sending waves of pleasure through their mouths. The kiss was soft and nice, not too forceful or rushed. Honoka honestly believed at that moment that a sensation softer than the lips of her little sister did not exist. After a minute Yukiho picked up the pace and her sister quickly followed. Their tongues were engaged in a graceful symphonious dance as waves of pleasure continue to excite them to the core of their beings but to the sister's displeasure, they had to part after a few minutes for the need to breathe had higher priority, unfortunately.

Sharing that kiss seemed to have cleared the sister's minds seeing that they grasped the fact that they just sprinted pass a line that should never be crossed but neither had the slightest hint of regret as they secretly wanted to continue.

"H-how was that, onee-chan?" Yukiho asked. 'I think I'm going to get addicted to her lips, that was nothing like when Alisa kissed me.'

Honoka stayed quiet for about half a minute with each second chipping away at her imouto's heart.

After finally returning to reality, the ginger voiced her opinion.

"Can we do it again?"

Did I say opinion? I meant request because one kiss was not enough for Honoka, it was as if Yukiho triggered something inside her sister. Something Yukiho would find out about later that night—something that required all of Honoka's might and willpower to ignore or at least resist for now. As for Yukiho, the speeding up of her heartbeat, the pleasant heat she felt traveling downwards, and the innocent joy she felt from knowing that Honoka enjoyed the kiss as much as she did give her a clear answer before she could understand the question's implications.

"Okay, I'm going to go get a drink first, I'll be right back." The brunette got up and left without waiting for any reply and as she was walking back to her sister's room after a very short drink, she confirmed that their parents were asleep. A smile slowly formed on her face, not being surprised by her own actions of making sure they wouldn't get caught as she entered the bedroom where Honoka was waiting for her, already under the covers with one hand holding onto the sheet while the other was out of view. Yukiho smiled at the sight as she closed the door and climbed into the bed.

"Onee-chan, do you think I could sleep with you tonight?"

Honoka produced an innocent smile that masked the seductive tone in her voice. "Sure, maybe we can sleep together like we used to."

After hearing those words, Yukiho proceeded to teach her sister how to kiss in various ways before finally going to sleep. The sisters slept together that night and every night they could without raising any suspicions whilst they share a secret both would not dare to repeat to anyone else.

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 **Author's Note:**

That's it for my first fanfic story, those who have read this story already and wanted some sort of sequel it's coming because there were so many unanswered questions. I am essentially finished with the first chapter so it took a lot of willpower not to upload it out of pure excitement after I was finished rewriting this. I want to upload the story when it's complete or when I am finished with most of it. I don't know when that will be but when it's done let's see how everyone else handles the recent development in Honoka's love life in the sequel "Imouto Sensei: Consequences."


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